Short answer
A fake IW371471 usually falls apart on three details: the printed dial text, the subdial hands, and the finish of the movement under the display back. On a real watch the "IWC" and "SCHAFFHAUSEN" lettering is thin, crisp, and sits flat against the dial. On most fakes it looks slightly heavy or sits a touch high. The chronograph and running-seconds hands should reset to zero dead on every time. On copies they drift, or stop a hair off center. If those three check out, move on to the case work and the paperwork.
What the IW371471 actually is
The reference belongs to the 3714 Portugieser Chronograph family, so the core specs carry across: a 40.9 mm stainless steel case, about 12.3 mm thick, 20 mm lugs, and a rating of 30 m (3 bar). Inside sits IWC calibre 79350, an automatic chronograph built on the Valjoux 7750 architecture, running at 28,800 vph with roughly 44 hours of power reserve. Sapphire crystal on top, sapphire display back on the bottom. The suffix in the reference number tells you about dial color, hands, and finish. It does not tell you that you are looking at a different watch.
The dial is where most copies give up
Look at the applied numerals first. Real ones are polished metal, set into the dial with tight, even feet, and they catch light along a clean bevel. Fakes use thinner plating, and the edges look rounded under a loupe. Next, the two subdials sit stacked at 12 and 6. Their hands are thin and straight, with a flat polished top. Copies often show a slightly fat hand or a matte finish that kills the reflection.
Then the date aperture, on references that have one. The font on a real IWC is narrow and sharp, centered in the window with even gaps on all four sides. Copies sit the disc low or high, and the numerals look rounder and bolder. Finish with the "SWISS MADE" print at 6 o'clock. It should be fine, even, and black, not smudged or half printed.
Case, lugs, and pushers
Run a fingernail along the lug edges. Genuine cases have a crisp transition between brushed top surfaces and polished flanks, and the edges are sharp enough to feel. Cheap copies round those edges off during polishing. The chronograph pushers should travel with a firm, short click and return on their own. Mushy pushers or ones that wobble side to side are a bad sign. Also check weight and balance in the hand. Steel is steel, but the thickness of the case walls matters, and a hollow-feeling case with thin lugs is not right.
Movement and caseback
Turn the watch over. Calibre 79350 shows decorative finishing, Geneva stripes on the bridges, and a rotor with clean, deep engraving. Many fakes drop in a stock 7750 clone with a printed rotor or a thin decorative plate over a cheaper movement. Look at the engraving depth on the caseback ring too. Factory laser engraving on a real IWC is even and slightly recessed. Aftermarket engraving looks shallow and grainy.
Box, papers, and the price test
This is the step that settles most arguments. A steel 3714-family Portugieser Chronograph trades on the secondary market in the rough range of five to eight thousand US dollars, depending on condition, box, papers, and seller. Anything offered at a fraction of that is either damaged, stolen, or fake. Ask for the original warranty card, the serial on the caseback, and any service receipts. A seller who will not show the movement or will not meet at a dealer for an inspection is telling you something.
Quick checklist
- Dial lettering thin, flat, and even
- Subdial hands reset to zero and align perfectly
- Applied numerals polished with sharp bevels
- Date font narrow and centered in the window
- Lug edges crisp, not rounded from over-polishing
- Pushers firm with a short click
- Movement shows real finishing, not a printed rotor
- Price and paperwork match the real market
What good replicas get right
Worth being honest here. The better copies nail the overall silhouette, the case diameter, and the look on the wrist from a few feet away. That is exactly why the tells live in the small things: printing weight, hand finishing, subdial alignment, and the movement. If you are buying on the secondary market, budget for a watchmaker to open the case. Ten minutes on a bench beats a month of arguing with a seller.